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Old 3rd September 2018, 02:09   #3135  |  Link
manolito
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Join Date: Sep 2003
Location: Berlin, Germany
Posts: 3,078
@MrC

Sorry I have to bug you with another request to change the A2D behavior for progressive 23.976 clips with pulldown flags...

Turns out that some of my previous findings about source filter behavior for such sources were wrong.
https://forum.doom9.org/showthread.p...21#post1850321

These statements are not true:
Quote:
The problem with A2D is that whenever DSS2Mod or DirectShowSource or FFmpegSource is used then the frame rate reported by MediaInfo is included in the call for the source filter. This will give incorrect results. If MediaInfo reports 2:3 pulldown then the frame rate for the source filter call should be 29.97 (or it could be omitted).

The reason for this incorrect behavior is that all the above source filters have no option to remove pulldown flags with a "Forced Film" option like DGIndex. They all honor the pulldown flags and serve a "pseudo-interlaced" output to AviSynth.
I recently did some more thorough tests about source filter behavior for such sources, have a look here:
https://forum.doom9.org/showthread.p...21#post1850321

Mainly AVStoDVD should use these procedures for the different source filters:

1: DGIndex / DGDecode
Basically leave it as it is. Only add the D2V parameter to the TFM call like:
TFM(d2v="my_d2v_file").TDecimate()

2: FFmpegsource
Use 23.976 as the fps value. Do not invoke IVTC

3: DSS2Mod and DirectShowSource
Use 23.976 as the fps value. Do not invoke IVTC


FFmpegSource does not honor the pulldown flags. When called without fpsnum/fpsden it will decode to 23.976.

DSS2Mod and DirectshowSource when called without an "fps=" parameter will decode to 29.97. But this is misleading because it does not honor the pulldown flags. Instead it decodes to 23.976 first and then adds duplicate frames to reach the 29.97 frame rate. Quite stupid. A2D should add the "fps=23.976" parameter to avoid this stupid behavior.


Alright, you won't like these new findings, I apologize for having misled you. The DSS2Mod/DirectShowSource way of outputting 29.97 but with dupes instead of repeated fields got me on the wrong track.


Cheers
manolito
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